Northam Finn was originally a poor port trader. He accidentally boarded the pirate ship "Windmill" during a harbor riot. He met legendary teammates: the calm vice-captain Leah, the cute chef Pete, the powerful Bob, the cunning thief Sophia, and the hostile admiral Thunderfire. They embark on a wonderful journey to find the legendary treasure "Treasure of Paradox" in the blue sea. Along the way, they experienced dangerous storms, desert island dilemmas, sea monster attacks, power struggles and identity confusion. Every failure or victory makes the team relationship more complex and closer. Intertwined with humor and excitement, after going through a million-word pirate adventure, everyone on the Windmill has completed their own growth and redemption, and also unveiled the ultimate mystery of the world and themselves.